Clay is a highly versatile and durable construction component that alongside stone and wood, is one of the oldest and most influential building materials on earth. This course looks at the history of clay in roofing and how this impacted and shaped modern roof tiles. The manufacturing process, roofing legislation and the different types and formats of clay tiles are also considered.

In this section
- The history of clay roofing
- Cultural influences on roof tile design
- The roots of modern roofing

Navigate through each step of the CPD using the left and right arrows to review the content. At the end of each section are some questions, these are required if you wish to obtain a certificate upon completing the course.

Clay is a versatile material that can produce a wide range of colours, shapes and surfaces. The colour spectrum ranges from super white, through classic red and deep oranges to brown and coal-black, it is usually influenced by the soil contents in which it is found.

Why use clay?

Used for thousands of years in construction worldwide, clay remains the most efficient, cost effective and sustainable solution for modern buildings.

Clay is strong, durable and builds in sound and temperature control benefits. Its natural properties mean that it is able to provide complete, long term sustainability, giving a building life of hundreds of years with little or no maintenance.

From sustainability credentials and build quality to the ease of use on-site, clay as a material is equipped to meet every demand of modern construction.

Alluvial clay

Alluvial clay consists of silt, sand, gravel, and organic matter. It usually found close to riverbeds, across floodplains and natural deltas.

Which civilisation was the first to use clay as a building product? The Egyptians, Greeks and Romans are all amongst the early cultures to have utilised clay.

However, history suggests that the first use was in the alluvial plains between Tigris and Euphrates in ancient Mesopotamia, which would be modern day Iraq.

Mesopotamia is one of the earliest known developments of the Neolithic or Agricultural Revolution from around 10,000 BC, when there was a wide-scale transition of many human cultures from a lifestyle of hunting and gathering to one of agriculture and settlement.

Mesopotamia

Map showing the historical region of Mesopotamia

The transition to agriculture and settlements made it possible to sustain increasingly larger populations, which had a profound impact on creativity and invention.

The Mesopotamians inspired some of the most important developments in human history including the invention of the wheel, cursive script, mathematics, astronomy, agriculture, beer and clay bricks.

Clay bricks were produced in vast quantities to build great cities and complex structures.

Ziggurat Temple

Ziggurat structure on which the temple sits at the top as close to the heavens as possible

Ziggurats were massive structures, with a terraced compound of successively receding stories or levels, which included a temple complex as well as other buildings.

The Ziggurats were thought to be cosmic mountains or ladders to heaven with the temples presiding at top to be nearer to the gods. These structures also provided a good vantage points and look outs for generals, making it easier to defend against enemy attacks.

Djenne, Mali, West Africa

The Great Mosque in Djenne in central Mali, constructed between 1200 to 1300 A.D

Djenne (pronounced Jenna) Mosque in Mali, West Africa is one of the world’s largest mud-brick structures and is a great example of this style of ancient building. The site requires constant maintenance and is resurfaced every year after the seasonal rains, in a ceremony that involves the local community.

The wooden posts adorning the sides enable workers to climb up the massive building during the restoration process.

Djenne, Mali, West Africa

Workers scale the wooden posts annually to repair and restore the ancient building

What led to the use of clay as a roofing material?

Historic roofing materials

Leaves and palms have been used for thousands of years for roofing

Historic roofing materials

Bamboos can be useful building materials due to their high compressive and tensile strengths that can rival wood, brick, concrete and steel

There are various claims throughout history for where the first roof tile originated, but probably the most reputable of these is Historia Naturalis (Natural History) written in AD77 by Gaius Plinius Secundus, better known as Pliny The Elder.

Pliny’s Natural History was a magnificent encyclopaedia that recorded all known sciences, it included 37 books, organised into ten volumes and covered a huge range of subjects. It was also the precursor to modern encyclopedias.

Pliny the Elder was a Roman author, naturalist, philosopher and a naval and army commander of the early Roman Empire

The history of the first tiles is intertwined with the the tale of Agrippa, who was a Roman General and school friend of Octavia. Octavia went on to become Emperor Augustus and together with Agrippa they conquered, united and ransacked foreign countries to establish the Roman Empire.

Agrippa then succeeded Augustus as Emperor and transformed Rome into a city of marble, building the Pantheon, the port of Misenum and numerous fantastic aqueducts.

However according to Pliny’s Natural History, it was Agrippa’s son, Herod Agrippa II, that was responsible for the production of the first tiles, which were constructed in marble and stone.

Flat stone roof tiles. modern tiles are usually made of clay but can also may be made of stone, wood, plastic, concrete, or solar panels.

Plain tiles

The evolution of plain tiles

The origins of plain tiles came initially from large leaves which were found in jungle, forest and woodland areas, these were used overlapped on simple roof structures to keep out the rain.

The next stage in the evolution of roofing was the change from leaves to using split pieces of timer (shingles). There was then a move from wooden shingles towards more robust durable tiles which led to the types plain tiles which we are familiar with today.

This was a very straightforward linear development.

The evolution of profiled tiles

The evolution of profiled tiles followed two different but similar routes to that of plain tiles.

Tegula and ImbrexTegula and Imbrex uses a flat plate undertile laid butted together (Tegula) with a tapered roll tile (Imbrex) bedded onto the joints. This became widely known as the Roman tile – despite being of Greek descent.

Under and Over TileUnder and Over Tiles use the same principles as the Tegula and Imbrex but are curved in their profile. This style of tiles became associated with the Spanish and so became recognised as Spanish tiles, which evolved later into the modern familiar pantile shape. Examples of this popular type of roof can be found across various Mediterranean countries.

How and where were the first clay roof tiles made?

Clay preparation

This sequence illustrates the making of under and over tiles in India

The previous pictures are contemporary but illustrate the the traditional manufacturing technique.

There is a popular myth that traditionally tiles were formed over a suitable shape, such as a female thigh, although the previous images show a shaped form.

A twist in the tale!

Early Chinese records suggest roof tiles were being produced as early as BC 2700

Early Chinese records suggest roof tiles were being produced there in BC 2700, roughly the same time as the Mesopotamians. If true, this surpasses the claims of both the Romans and the Greeks.

The tiles in the previous image are similar to Tegula and Imbrex shapes developed by the Greeks, which later become popular with the Romans.

The Greeks may have not been first to produce tiles, but evidence suggest that they were the first to understand the firing process which greatly improved durability. The earliest fired clay roof tiles that have been identified are plain tiles from Lerna in Greece, dating back to about BC 1800. Lerna tiles were approximately 175mm long and similar to today’s plain tile.

The Stoa of Attalos (also spelled Attalus) was a stoa (covered walkway or portico) in the Agora of Athens, Greece

The Stoa of Athens built in 150BC, was a commercial centre commissioned by King of Pergammon as gift to Athens. It was roofed with clay tiles.

This previous image shows the modern reconstruction of this building, which used a replica of the original Greek Tegula and Imbrex tile. The tiles were re-created for this project when the Stoa was re-built from excavated ruins in 1956.

This tile is in two parts, an underside (Tegula) and a smaller covering tile (Imbrex).

“Tegula and Imbrex” Roman tiles

The Romans were the first to make clay tiles in Britain, at the time it was believed that they had pioneered the use of them.

The tiles the Roman’s produced in Britain were similar to Greek tiles we’ve previously seen.

Roman tiles produced for Minley Manor in Surrey

The Spanish tile is completely tapered and used “under” and “over” as the name suggests.

It is exactly the same principle as Greek Tegula and Imbrex tile but it is curved. The different styles of tiles influenced architecture in Britain and caused a blurring of the differences between Greek, Roman and Spanish tiles.

Example of a Spanish style tile

Ironically, the Spanish style tile was used for the Verulamium Museum in St Albans, a Roman town

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Question

Which was the first civilisation to utilise clay as a building material?